Firearm Gas System

ABSTRACT

A gas system for a firearm is presented. The gas system has an elongate static tube and an elongate dynamic tube in a telescoping relationship. The elongate static tube defines a first internal passageway and is attachable to a portion of the gas block of the firearm. The elongate dynamic tube is telescopingly engaged with the elongate static tube. The elongate dynamic tube defines a second internal passageway in communication with the first internal passageway.

FIELD OF THE INVENTION

This invention relates generally to rifle manufacturing, and moreparticularly to a gas system configured for use with a rifle.

BACKGROUND OF THE INVENTION

Traditional direct impingement gas operation does away with a separategas cylinder, piston, and operating rod assembly to cycle the action ofa firearm. High-pressure gas acts directly upon the bolt and carrierthereby saving weight, lowering costs, and reducing the mass of theoperating parts, and thereby the wear on mechanical parts due tomovement. A static tube is connected into the gas block and the gasblock attaches to the gun's barrel and covers a portion of the gas porton the barrel. The gas key attached to the bold carrier slides over thetube when the bolt is in the chambered position. This system worksbecause, as the bullet clears the gas port, a portion of the gas isforced down the gas tube and acts directly upon the bolt and carrier tostart the cycle.

The main disadvantage of direct impingement is that the breech of thefirearm's firing mechanism becomes fouled more quickly due to beingexposed to the propellants of the cartridge. This is caused by solidsfrom the high-temperature gas condensing on the bolt face and primaryoperating mechanism. The combustion gases contain vaporized metals,carbon, and impurities in a gaseous state until they contact cooleroperating parts. The deposits increase friction on the bolt's cammingsystem leading to malfunctions, so that thorough and frequent cleaningis required to ensure reliability. The amount of fouling depends uponthe rifle's design as well as the type of propellant powder used.

A further disadvantage of traditional direct impingement is thatcombustion gases heat the bolt and bolt carrier as the firearm operates.This heating causes essential lubricant to be “burned off”. Lack ofproper lubrication is a very common source of weapon stoppages ormalfunctions. These combined factors reduce service life of these parts,reliability, and mean time between failures.

SUMMARY

Presented herein is a gas system for a firearm. The gas system comprisesan elongate static tube and an elongate dynamic tube in a telescopingrelationship. The elongate static tube defines a first internalpassageway and is attachable to a portion of the gas block of thefirearm. When the elongate static tube is attached to the gas block, thefirst internal passageway is in communication with the aperture of thegas block. Also presented is an elongate dynamic tube that istelescopingly engaged with the elongate static tube. The elongatedynamic tube defines a second internal passageway in communication withthe first internal passageway.

Firing the firearm causes high pressure gases enter into the first andsecond internal passageways via the aperture in the barrel, therebyextending the telescoping relationship between the static tube and thedynamic tube and forcing the bolt carrier proximally, which expels thespent shell.

Related methods of operation are also provided. Other apparatuses,methods, systems, features, and advantages of the firearm gas systemwill be or may become apparent to one with skill in the art uponexamination of the following figures and detailed description. It isintended that all such additional apparatuses, methods, systems,features, and advantages be included within this description, be withinthe scope of the firearm gas system, and be protected by theaccompanying claims.

DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate certain aspects of the instantinvention and together with the description, serve to explain, withoutlimitation, the principles of the invention. Like reference charactersused therein indicate like parts throughout the several drawings.

FIG. 1 is side view of a gas system for a firearm of the presentapplication, showing the gas system coupled to the firearm, according toone aspect.

FIG. 2 is a perspective view of the gas system of FIG. 1, showing anelongate static tube and an elongate dynamic tube of the gas system.

FIG. 3 is a perspective view of the elongate static tube of FIG. 2,according to one aspect.

FIG. 4 is a perspective view of the elongate dynamic tube of FIG. 2,according to one aspect.

FIG. 5 is a perspective view of a gas block of the firearm of FIG. 1,according to one aspect.

FIG. 6 is a perspective view of a gas key of the firearm of FIG. 1,according to one aspect.

DESCRIPTION OF THE INVENTION

The present invention can be understood more readily by reference to thefollowing detailed description, examples, and claims, and their previousand following description. Before the present system, devices, and/ormethods are disclosed and described, it is to be understood that thisinvention is not limited to the specific systems, devices, and/ormethods disclosed unless otherwise specified, as such can, of course,vary. It is also to be understood that the terminology used herein isfor the purpose of describing particular aspects only and is notintended to be limiting.

The following description of the invention is provided as an enablingteaching of the invention in its best, currently known aspect. Thoseskilled in the relevant art will recognize that many changes can be madeto the aspects described, while still obtaining the beneficial resultsof the present invention. It will also be apparent that some of thedesired benefits of the present invention can be obtained by selectingsome of the features of the present invention without utilizing otherfeatures. Accordingly, those who work in the art will recognize thatmany modifications and adaptations to the present invention are possibleand can even be desirable in certain circumstances and are a part of thepresent invention. Thus, the following description is provided asillustrative of the principles of the present invention and not inlimitation thereof.

As used herein, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. Thus, forexample, reference to a “firearm” includes aspects having two or morefirearms unless the context clearly indicates otherwise.

Ranges can be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another aspect includes from the one particular value and/orto the other particular value. Similarly, when values are expressed asapproximations, by use of the antecedent “about,” it will be understoodthat the particular value forms another aspect. It will be furtherunderstood that the endpoints of each of the ranges are significant bothin relation to the other endpoint, and independently of the otherendpoint.

As used herein, the terms “optional” or “optionally” mean that thesubsequently described event or circumstance may or may not occur, andthat the description includes instances where said event or circumstanceoccurs and instances where it does not.

Terms used herein, such as “exemplary” or “exemplified,” are not meantto show preference, but rather to explain that the aspect discussedthereafter is merely one example of the aspect presented.

Additionally, as used herein, relative terms, such as “substantially”,“generally”, “approximately”, and the like, are utilized herein torepresent an inherent degree of uncertainty that may be attributed toany quantitative comparison, value, measurement, or otherrepresentation. These terms are also utilized herein to represent thedegree by which a quantitative representation may vary from a statedreference without resulting in a change in the basic function of thesubject matter at issue.

In one aspect, presented herein is gas system 10 for a firearm 12. Inone aspect, the firearm can comprise an AR15 or similar rifle. The gassystem comprises an elongate static tube 14 and an elongate dynamic tube16 in a telescoping relationship. In one aspect, the gas system 10 canfurther comprise at least one of a gas block 24 and a gas key 40.Optionally, however, the gas block and/or the gas key can be an elementof the firearm. The elongate static tube and the elongate dynamic tubecan be formed from aluminum, stainless steel, or any other substantiallyrigid material with heat tolerance and corrosion resistance.

In an exemplified aspect, the elongate static tube 14 defines a firstinternal passageway 18 extending between a proximal end 20 and a distalend 22 of the elongate static tube. In another aspect, the distal end ofthe elongate static tube 14 can be attachable to a portion of the gasblock 24 coupled to a barrel 46 of the firearm. In this aspect, when theelongate static tube is attached to the gas block, the first internalpassageway can be in communication with an aperture 26 defined in thegas block 24. Note that the aperture in the gas block can be incommunication with an exhaust port in a barrel 46 of the firearm 12through a gas duct 27 defined in the gas block 24. The attachmentbetween the elongate static tube 14 and the gas block can be aconventional attachment means, such as a threaded relationship, a weld,and the like. The attachment, in an exemplified aspect, can besubstantially sealed so that fluid cannot escape between an outersurface 28 of the elongate static tube and the aperture 26 of the gasblock.

In another aspect, the elongate dynamic tube 16 can be telescopinglyengaged with the elongate static tube 14 such that the elongate dynamictube can slide longitudinally relative to the elongate static tube. Inthis aspect, the elongate dynamic tube 16 can defines a second internalpassageway 30 extending between a proximal end 32 and a distal end 34 ofthe elongate dynamic tube. In another aspect, when the elongate dynamictube 16 is coupled to the elongate static tube 14, the second internalpassageway can be in communication with the first internal passageway18. As can be appreciated, in an exemplified aspect, an internaldiameter 36 of the elongate dynamic tube can be larger than an externaldiameter 38 of the elongate static tube such that the elongate dynamictube 16 can slide or telescope over at least a portion of the elongatestatic tube. In one aspect, the external diameter of the elongate statictube can be between 2/1000″ and 10/1000″ smaller than the internaldiameter of the elongate dynamic tube. In another aspect, that tolerancecan be about 3/1000″. It is contemplated in another aspect that thereverse can also be true, such that the elongate dynamic tube 16 slidestherein the first internal passageway 18. In this aspect, an internaldiameter of the elongate static tube 14 can be larger than an externaldiameter of the elongate dynamic tube. In an exemplified aspect, theinner tube can be lubricated with Boron or other dry film lubricant andthe like.

In one aspect, the proximal end 32 of the elongate dynamic tube 16 canbe attachable to a portion of a gas key 40 of the firearm. In thisaspect, when the elongate dynamic tube is attached to the gas key, thesecond internal passageway 30 can be in communication with an aperture42 defined in the gas key 40. The attachment between the elongate statictube 14 and the gas key can be a conventional attachment means, such asa threaded relationship, a weld, and the like. The attachment, in anexemplified aspect, can be substantially sealed so that fluid cannotescape between an outer surface 44 of the elongate dynamic tube and theaperture 42 of the gas key. In another aspect, the gas key can befixedly attached to a bolt carrier 48 of the firearm 12, so thatmovement of the gas key can move the bolt carrier similarly. Note thatthe aperture 42 in the gas key 40 can be in communication with the boltcarrier 48 of the firearm 12 through a gas duct 50 defined in the gaskey.

It is also contemplated that the cross-sectional shapes of the elongatestatic tube 14 and the elongate dynamic tube 16 be complimentary. In oneexemplified aspect, the cross-sectional shapes can be substantiallycircular, oval, rectangular, square, or star shaped.

In one aspect, the elongate static tube 14 and the elongate dynamic tube16 can be installed above the barrel 46 of the firearm 12. The elongatetubes can be, for example, installed 0.787″ about the barrel. In anotheraspect, the elongate static tube 14 and the elongate dynamic tube 16 canbe substantially equidistant from the barrel 46. In another aspect, atleast one of the elongate tubes can be substantially parallel to thebarrel.

In use, firing the firearm 12 causes high pressure gases to enter intothe first internal passageway 18 and second internal passageway 30 viathe gas port in the barrel 46, the gas duct 27 defined in the gas block24 and the aperture 26 defined in the gas block. The high pressure gasescan urge the elongate dynamic tube 16 longitudinally, telescopinglyrelative to the elongate static tube 14. That is, the high pressuregases can urge the elongate dynamic tube proximally away from the gasblock, which also urges the gas key 40 and a bolt carrier 48 proximally,thereby expelling a spent shell. The gas system 10 can be normally besubstantially sealed, with the exception of the distal end 22 of theelongate static tube 14 which is open to and in fluid communication withthe barrel in order to receive the high pressure gases into the gassystem 10. When the firearm 12 is fired, the high pressure gases behindthe bullet propel the bullet through the barrel. As the bullet clearsthe gas port in the barrel 46, the gas pressure travels through theport, into the gas block 24, into the first internal passageway 18 andinto the second internal passageway 30, forcing the proximal end 32 ofthe elongate dynamic tube 16 proximally away from the gas block. Becausethe proximal end of the elongate dynamic tube is attached to gas key 40,and the gas key is attached to the bolt carrier, the bolt carrier 48 canbe forced proximally to start the cycle.

In still another aspect, at least one exhaust port 52 can be defined inthe bolt carrier 48 adjacent the proximal end 32 of the elongate dynamictube 16. In one aspect, the at least one exhaust port can comprise twoexhaust ports. The at least one exhaust port 52 can normally be in aclosed position. In this aspect, when a bolt of the firearm 12 is pusheddistally (i.e., towards the gas block 24), gas can be blown into theatmosphere through the exhaust port(s) defined in the bolt carrier 48.Any gas and other particles that remain in the gas system 10 can besucked out of the distal end 22 of the elongate static tube 14 when thebullet exits the barrel 46. In this manner, no significant gas and/orpollutants exit the gas system into other portions of the firearm, suchas the upper receiver, to cause the gas and/or pollutants to foul thebolt assembly. This configuration also can enable the cycling pressureto be controlled with more precision due to the fact that telescopingtubing increases volume as the bolt is forced proximally. This expansionof the volume expands the gases and aids in the cooling of the gases aswell.

Although several aspects of the invention have been disclosed in theforegoing specification, it is understood by those skilled in the artthat many modifications and other aspects of the invention will come tomind to which the invention pertains, having the benefit of the teachingpresented in the foregoing description and associated drawings. It isthus understood that the invention is not limited to the specificaspects disclosed hereinabove, and that many modifications and otheraspects are intended to be included within the scope of the appendedclaims. Moreover, although specific terms are employed herein, as wellas in the claims that follow, they are used only in a generic anddescriptive sense, and not for the purposes of limiting the describedinvention.

What is claimed is:
 1. A gas system for a firearm having a bolt, a boltcarrier, a gas key attached to the bolt carrier, a receiver, a barreldefining a gas port, a gas block attached to the barrel having anaperture in communication with the gas port, the gas system comprising:an elongate static tube defining a first internal passageway, theelongate static tube having a proximal end and a distal end, the distalend being attachable to a portion of the gas block where, when attachedto the gas block, the first internal passageway is in communication withthe aperture of the gas block; and an elongate dynamic tube having aproximal end and a distal end, the elongate dynamic tube beingtelescopingly engaged with the elongate static tube wherein the proximalend of the elongate dynamic tube is configured to be fastened to the gaskey of the firearm, and wherein the elongate dynamic tube defines asecond internal passageway that is in communication with the firstinternal passageway; wherein firing the firearm causes high pressuregases to enter into the first and second internal passageways via theaperture in the barrel, thereby extending the telescoping relationshipbetween the static tube and the dynamic tube and forcing the boltcarrier proximally.
 2. The gas system of claim 1, wherein the first andsecond internal passageways are substantially sealed, with the exceptionof the distal end of the elongate static tube.
 3. The gas system ofclaim 1, further comprising at least one exhaust port defined adjacentthe proximal end of the dynamic tube, wherein, the exhaust port isnormally closed.
 4. The gas system of claim 3, wherein when the bolt ispushed forward, the at least one exhaust port is opened to enablerelease of gas.
 5. The gas system of claim 4, wherein when the gas isreleased and the bolt is moved distally, the at least one exhaust portreturns to the closed position.
 6. A firearm system, comprising: afirearm having a bolt, a bolt carrier, a gas key attached to the boltcarrier, a receiver, a barrel defining a gas port, a gas block attachedto the barrel having an aperture in communication with the gas port; anelongate static tube defining a first internal passageway, the elongatestatic tube having a proximal end and a distal end, the distal end beingattachable to a portion of the gas block where, when attached to the gasblock, the first internal passageway is in communication with theaperture of the gas block; and an elongate dynamic tube having aproximal end and a distal end, the elongate dynamic tube beingtelescopingly engaged with the elongate static tube wherein the proximalend of the elongate dynamic tube is configured to be fastened to the gaskey of the firearm, and wherein the elongate dynamic tube defines asecond internal passageway that is in communication with the firstinternal passageway; wherein firing the firearm causes high pressuregases enter into the first and second internal passageways via theaperture in the barrel, thereby extending the telescoping relationshipbetween the static tube and the dynamic tube and forcing the boltcarrier proximally.
 7. The gas system of claim 6, wherein the first andsecond internal passageways are substantially sealed, with the exceptionof the distal end of the elongate static tube.
 8. The gas system ofclaim 6, further comprising at least one exhaust port defined adjacentthe proximal end of the dynamic tube, wherein, the exhaust port isnormally closed.
 9. The gas system of claim 8, wherein when the bolt ispushed forward, the at least one exhaust port is opened to enablerelease of gas.
 10. The gas system of claim 9, wherein when the gas isreleased and the bolt is moved distally, the at least one exhaust portreturns to the closed position.